admin The fibers that are already used for paper manufacturing process are known as secondary fiber or recycled fiber. Different grade of waste paper are the sources of it. Even, dry end broke, cutter and finishing section broke are also included in secondary fiber. This fiber is an important part for paper productions. The wastepaper may … Read more
Wood chipper is used in paper mill to produce chips from pulpwood so that cooking chemicals penetrate the wood quickly, completely and uniformly during manufacturing of chemical pulp or mechanical pulp. The process from pulpwood to chips is known as chipping process. The sizes of the good quality chips can be 5/8 to 5/4 inch … Read more
Optical brightening agents are additives which are used in the paper industries to enhance whitening effects of papers. These chemical compounds absorb light in the ultraviolet and violet region (usually 340-370nm) and re-emit light in the blue region (typically 420-470 nm). It gives a fluorescent effect that masks the inherent yellowness of the fiber and … Read more
The paper machine headbox is an equipment that supply very low consistency stock into the forming section uniformly. The formation and uniformity of the final paper product depends on the dispersion of the fiber and fillers. The furnish delivery system varies on the construction of the headbox. It has a significant effect on paper qualities. … Read more
The Kappa number of pulp is an indication of the lignin content or bleachability of pulp. We use it to estimate the required amount of bleach chemicals to achieve targeted brightness. If the kappa number value is higher then, the required bleaching chemicals are also higher. On the other hand low kappa pulps are easier … Read more
Hydrogen peroxide is a total chlorine free (TCF) bleaching agent. It is appropriate for chemical, mechanical and recycled pulp to achieve a wide range of brightness. It has both oxidizing and reducing properties which is pH depended. The chemical formula of this bleach is H2O2. Pure hydrogen peroxide is very light blue color but colorless … Read more
Chlorine dioxide is an oxidizing agent for pulp bleaching. The chemical formula of this chlorine dioxide bleach is ClO2. It is a yellowish-green gas, bad odor and liquefied in 11⁰C which is red in color. It is an ECF (elemental chlorine-free) bleaching process which is currently most important bleaching technology in worldwide, especially for sulfate … Read more
Hypochlorite bleach is an oxidizing agent. There are two types of hypochlorite bleaching agent that are used in pulp and paper industries such as calcium hypochlorite and sodium hypochlorite. Generally, this stage is placed after chlorination and alkali extraction stages. It can be single stage or multiple stage process. Single stage hypochlorite bleaching process is … Read more
Alkaline extraction stage is essential after chlorination bleaching stage is to remove chlorinated and oxidizing lignin products from the pulp. It is also help to reactivate the remaining lignin for the next oxidation stage. All the chlorinated lignins are not soluble in the water. About 40-42% of them are soluble in water and wash out. … Read more
Christmas tissue paper is a special type or non-especial type tissue paper. During Christmas many people decorate their house. For decoration tissue paper can be used and makes the holidays bright. For this purposes a special type tissue paper are produced. These may be colors such as blue, light blue, green, light green, pink, purple, … Read more